1. Field of the Invention
The present invention relates to plasma display panel, and more particularly, to a plasma display panel whose structure is improved to realize a large image and a method for fabricating the same.
2. Description of the Related Art
In a usual plasma display panel, discharge gas is injected between a pair of substrates facing each other. Ultraviolet rays which are generated during discharge excite phosphors, thereby displaying an image. Plasma display panels are classified into a direct current type and an alternating current type according to the type of discharge and classified into a counter discharge type and a surface discharge type according to the structure of electrodes.
FIG. 1 show a conventional plasma display panel. Referring to FIG. 1, a panel 10 includes a front substrate 11 and a rear substrate 12. Common electrodes 13 and scanning electrodes 14 alternate on the bottom surface of the front substrate 11 in a striped pattern. Bus electrodes 15 are formed on the bottom surfaces of the common and scanning electrodes 13 and 14 to reduce the line resistance of the electrodes 13 and 14. Each bus electrode 15 is a metal material narrower than the common or scanning electrode 13 or 14. A first dielectric layer 16 is formed on the bottom surface of the front substrate 11 such that the common and scanning electrodes 13 and 14 and the bus electrodes 15 are embedded in the first dielectric layer 16. A protective layer 17, for example, a MgO layer, is formed on the bottom surface of the first dielectric layer 16.
Address electrodes 18 on the rear substrate 12 are orthogonal to the common and scanning electrodes 13 and 14 in a striped pattern. The address electrodes 18 are embedded in a second dielectric layer 19. A plurality of partition walls 100 on the second dielectric layer 19 are spaced apart by a predetermined distance. Red, green and blue light-producing phosphor layers 110 are located between the partition walls 100. A plurality of panels 10 are assembled to implement a large image.
FIG. 2 show a conventional large plasma display panel. Referring to FIG. 2, the large plasma display panel includes a first front substrate 21, a second front substrate 22, a third front substrate 23 and a fourth front substrate 24. First, second, third and fourth rear substrates 210, 220, 230 and 240 are provided to face the first, second, third and fourth front substrates 21, 22, 23 and 24, respectively.
The first, second, third and fourth front substrates 21, 22, 23 and 24 are connected to one another along their edges to thereby form a single large front substrate 20. The first, second, third and fourth rear substrates 210, 220, 230 and 240 are connected to one another along their edges to thereby form a single large rear substrate 200.
To keep the large plasma display panel in a vacuum state, a first frit glass 25 is provided at the portion at which the first, second, third and fourth front substrates 21, 22, 23 and 24 come in contact with one another, and a second frit glass 250 is provided at the portion at which the first, second, third and fourth rear substrates 210, 220, 230 and 240 come in contact with one another.
In the conventional large plasma display plasma, a phenomenon in which an image is minutely sectioned occurs due to the first frit glass 25 and the second frit glass 250, thereby deteriorating picture quality. To overcome this phenomenon, the width of each of the first frit glass 25 and the second frit glass 250 where the substrates come in contact must be minimized. However, the first frit glass 25 and the second frit glass 250 are essential to keeping the vacuum airtightness of the plasma display panel. Therefore, the phenomenon of an image being sectioned is an unavoidable problem in the conventional large plasma display panel.
To solve the above problem, an object of the present invention is to provide a plasma display panel whose structure is improved to remove the phenomenon of an image being sectioned when a single large plasma display panel is fabricated by assembling a plurality of panels and a method for fabricating the plasma display panel.
To achieve the above object, in one aspect, the present invention provides a plasma display panel includes a plurality of front substrates for forming a display part for displaying an image, a plurality of rear substrates provided to be sealed to corresponding front substrates, a first frit glass with which the outer edge of the front and rear substrates are coated, an upper glass provided on the top of the plurality of front substrates, a lower glass which is provided on the bottom of the plurality of rear substrates and sealed to the upper glass, and a second frit glass with which the edge of the upper and lower glasses is coated.
In addition, the first frit glass is provided along the edge of the assembled plurality of front and rear substrates.
Further, the inner surface forming the display part in the plurality of front substrates and the inner surface of the plurality of rear substrates are not coated with the first frit glass.
Moreover, the lower glass is provided with a second evacuation hole at the same position as that of a first evacuation provided in the rear substrate.
In another aspect, the present invention provides a method for fabricating a plasma display panel, including the steps of preparing a plurality of front substrates for forming a display part for displaying an image and a plurality of rear substrates to be sealed to the corresponding front substrates; coating the edge of the plurality of front and rear substrates with a first frit glass; preparing an upper glass to be mounted on the top of the front substrates and a lower glass to be mounted on the bottom of the rear substrates and to face and to be sealed to the upper glass; coating the edge of the upper and lower glasses with a second frit glass; positioning the plurality of front and rear substrates between the upper and lower glasses and coating the outer side edge of the front and rear substrates with a third frit glass; sealing the front substrates to the rear substrates and sealing the upper glass to the lower glass; performing high temperature evacuation to remove impurities between the front and rear substrates; and injecting discharge gas between the front and rear substrates and removing an evacuation pipe.
In addition, in the step of coating the edge of the plurality of front and rear substrates with the first frit glass, the display part in the inner side of the front and rear substrates is not coated with the first frit glass, and the outer edge of the front and rear substrates is coated with the first frit glass.
Further, in the step of performing the high temperature evacuation, a second evacuation hole is formed in the lower glass such that the central axis of the second hole is the same as that of a first hole formed in the rear substrate. The evacuation is performed via the communicating first and second evacuation holes.